1. Technical Field
The invention relates to networked computer systems. More particularly, the invention relates to a method and system for automatically configuring multi-segment network device connections.
2. Description of the Prior Art
Computer network systems are inherently complex. A significant amount of technical education is required to understand, configure, and maintain any particular type of physical network, such as 10Base-T, Ethernet, Token Ring, or Token Bus networks. As the use of computer networks becomes widespread, new technicians are needed to maintain and operate those networks. These technicians may have little or no knowledge about networks, and may not ever fully understand networks, even with extensive training.
As a result, software schemes which can configure, maintain, or improve network conditions without requiring the user to have much specific technical knowledge are desirable. "Ease-of-use" and "user-friendly" schemes are often included in software applications that are embedded in, or located external to, the network devices. Such software applications are known as "intelligent network agents." An example of an intelligent network agent is disclosed in the U.S. patent application entitled, "Method and System for Automatic Detection of Bridged and Repeated Network Device Connections," U.S. Ser. No. 08/895,119, filed Jul. 16, 1997, and assigned to Hewlett-Packard Company.
The different types of network device connections between network links, along with their location in relation to a given hardware environment, are collectively known as a network's "topology."
For purposes of the discussion herein, a "repeater" is a device that is used to extend the length, topology, or interconnectivity of a physical cabling medium beyond that imposed by a single cable. Repeaters perform the basic actions of restoring the signal amplitude, waveform, and timing applied to the data signals.
For purposes of the discussion herein, a "bridge" is a multiport device connecting two or more network segments. When two stations on different network segments communicate with each other, the bridge forwards the packets between the two segments. When the stations are on the same segment, the bridge does not forward the packet to any other segment. The term "switch" can also be used interchangeably with the term "bridge."
One challenge facing a network administrator is correctly setting up a network. Setting up a network involves connecting devices together in such a way that they function as the administrator desires. An administrator who does not fully understand the workings of the devices, or the network itself, may not be able to set up the network properly. Unfortunately, there are no known satisfactory solutions to automatic configuration of external network device connections.
Physical connections in the network can create a loop. When such a loop occurs, it is very difficult or even impossible to exchange information reliably with other network software agents. Some network software agents may cease working altogether. Manually reconfiguring a network to remove loops requires a certain degree of skill, and can be time consuming.
A failure in a network link can cause loss of valuable data. It can therefore be desirable to provide a redundant connection to insure data continuity in the event of such link failure. The only known method for automatically removing a loop or automatically configuring such redundant connections is the Spanning Tree Protocol described in IEEE standard 802.1. However, this method cannot be implemented using repeaters.
It would therefore be an advantage to provide a new method and system for automatically configuring network links to attached devices which can be implemented with both bridging devices and repeaters. It would be a further advantage if such method and system also created redundant connections for increased device reliability, fixed network loops, and otherwise configured the devices to work together. It would be yet another advantage if such method and system were user-friendly and required no specific action on the part of the network administrator.